Process of making fertilizers.



nun'wm s-Anmmen, or NEW YGRK, at. Y.

PROCESS OF MAKING FERTILiz'ERs;

noseeoe. No Drawing.

To all whom it may concern Be it known that l, Lmwm SAARBACH, a citizen of the German Empire, and a resident of the borough of Manhattan, city,

county, and State of New York, have invented a certain new and useful Improvement in Processes of Making Fertilizers, of

which the followingis a specification.

This invention relates to a process of treating mineral phosphates containing carbonates by exposing them to the action of nitrogen oxids for the purpose of obtaining fertilizers containing nitrates or nitrites, or both, and phosphoric acid in available form.

It has for its object the elimination of the labor and cost of concentrating and separating the nitric acid, nitrites and nitrates obtaincd by the utilization of the nitrogenof the air by processes hitherto practised,' in case these products are intended for use in fertilizers. v

- I have found that nitrogen oxids (NO, N 0 and N 0,) will in the presence of sufficient quantities of moisture and oxygen, for instance the oxygen ofthe air, react readily with for example insoluble calcium phosphates, containing calcium carbonate, forming a combination of nitrate or nitrite of lime with phosphoric acid in available condition, which ingredients are excellent plant foods.

The following formula will illustrate a characteristic reaction which may take place in the operation of my process:

the use' of my process it is therefore more concentrated form.

It must, of course, be understood that the nitrogen. oxids which I employ in my proc-' ess maybe produced in any suitable manner, for instance'by the electric arc process or by the heat'of explosive combustion or by a carbon monoxid flame, etc. -It must also be understood that Ibis exceedingly difficult, if not impossible, to obtain any one of these nitrogen oxids separately from the .7 mothers, as there is a constant mutation from oxid (NO) primarily produced in the elec-' one of them to another. Thus the nitric Specification of Letters Patent. 7

Application filed May 11, 1911. Serial N0. 626,402.

tric furnace begins to change to nitrogen pero'xid (N 0,) when the temperature of the gas is reduced to about 600 C., taking up oxygen from the air with which it is diluted, and probably" also to nitrogen tri'oxid (N 0 (See Metallurgical and Chemical Engineering, Vol. IX, page 196, April, 1911.) Thus when these gases come into contact with the water there may be formed, and undoubtedly is formed in al most all cases, not only nitric acid but also nitrous I acid, according .to the formula,

2NO2+H1O=HNO3+HNO1L I The nitrous acid will form nitrites wherca's'the nitric acid will form nitrates. Moreover, when the nitrogen eroxid unites with the water to form the itric acid of the above fo mulas, there is formed nitric oxid,

which in turn unites with the oxygen of the air to form nitrogen peroxid for subsequent conversion into nitrlc ac d. It Wlll there fore he understood that my process con- Patented'Aug. 27-, 19 12. I

templates the presence of oxygen, prefcrably that of the air, for its best operation.

My process is of particular value in making possible the working up of low-grade phosphates, particularly those which contain a large percentage of carbonate of lime. According to the method now in use a'large quantity of sulfuric acid would be required to make the phosphoric acid available because a large amount of the sulfuric acid would be wasted in decom osing'the carbonates, and the finished prodilct would be overloaded with sulfate of lime. By my process these low-grade phosphates can be readily and cheaply converted into a fertilizer comprising two valuable constituents, namely available phosphoric acid and ni trates or nitrites of lime, or both,.withou't the formation of calcium sulfate, a portion of the nitrates or nitrites of lime originating from the decomposition of the carbonate of lime where this" substance is present. I

According to the character of the phosphatic raw material used, the fertilizer obtained by my process will contain variable amounts and proportions of phosphoric acid, nitrates or nit-rites, or both. These may be mixed with other fertilizers or potash salts to suit the requirements of different soils or crops.

I claim: cium carbonate, with nitrogen oxid in the 1. The process of manufacturing a ferpresence of moisture, substantially as and tilizer, which consists in treating low grade for the purpose'described. phosphate minerals containing a carbonate, In witness whereof, I have hereunto se 5 with nitrogen cxid in the presence of m0is--' my hand in the presence of two subscribing 15 tux-e, substantially as and for the purpose Witnesses.

described. s i LUDWIG sAARBAcH.

2. The process of manufacturing a fer- Witnesses tilizer, which consists in treating minerals JOHN A. FERGUSON,

10 which contain calcium phosphate and cal- JOHN A. KEHLENBECK, 

